This invention is in the field of bicycle exercisers.
Bicycle exercisers or ergometers have been used for some time in both athletic and medical-therapeutic applications. While those utilized primarily for exercise purposes, such as at a health club, need only provide an indication of speed of rotation of the flywheel of the ergometer, perhaps with the addition of an odometer, those exercise devices utilized for medical-therapeutic purposes require more precise determination of the power supplied by the patient using the ergometer.
There have been proposed various electrical and mechanical means for determining the speed of rotation of the flywheel of ergometer, as well as the amount of power delivered by the user. Often these speed determining devices are a part of a larger more complicated, system, such as for automatic loading of the flywheel. In all cases, these devices for indicating work have been relatively complex and generally expensive. Mechanical approaches to determining the power supplied by a person using an ergometer are subject to various mechanical difficulties such as breakdowns and need for replacement of worn parts. Externally-powered indicators include those shown in U.S. Pat. No. 2,784,591 to Shoor; U.S. Pat. No. 3,057,201 to Jaeger; U.S. Pat. No. 3,505,992 also to Jaeger; and U.S. Pat. No. 3,715,721 to Lulay et al. Some of these devices, and several others known in the art, utilize magnets and similar structures associated with the flywheel for providing the load on the flywheel rather than using the more standard belt-type load. However, such utilization of magnets is not relevant to the use of magnets for flywheel speed determination.
Previous mechanical methods for work determination have generally been less expensive than the purely electrical methods but are not as reliable. Further, among the electrical methods, none have been provided which are self-powered. The most relevant prior art patent of which applicant is aware is U.S. Pat. No. 3,767,195 to Dimick, which shows the use of a tachometer pickup including a magnet mounted on the flywheel activating a reed switch. Dimick, however, deals exclusively with an externally powered system and fails to apprehend the use of a pickup coil as set forth herein.